1. Technical Field
The invention relates generally to an improved overhead door lock. More particularly, the invention relates to an improved lock for use with overhead doors which are opened and closed either manually, or via an electric motor. Specifically, the invention relates to an overhead door lock for securing an overhead door in the closed position, but which also may be easily adjusted to place the lock in an inoperative position to allow the door to open and close via an electric motor.
2. Background Information
An ever increasing number of homes are constructed with garages for storing automobiles out of the elements, and for storing yard tools and the like. These garages are generally equipped with overhead doors of a variety of sizes which may be opened and closed over a large doorway. Further, as business becomes increasingly competitive, a growing number of businesses have shipping, storage, and receiving facilities which utilize overhead doors.
While overhead doors are often opened manually, the use of automatic motor operators to lift overhead doors is becoming increasingly popular in both the residential and commercial markets. Further, these motors are a necessity on many commercial overhead doors, as the size and weight of such doors make them cumbersome to be opened by an individual operator.
Whether the door is operated manually or automatically, the weight of the door is generally counterbalanced using either a torsional spring, or an extension spring. A torsional spring is unloaded when the door is in the closed position, and becomes loaded as the door is lifted. Inasmuch as the springs on each side are connected via a torsion rod, a lock is only necessary on one side of the door; but a lock may be provided on each side of the door for added security. However, inasmuch as a door counterbalanced with extension springs is fully loaded when the door is in the closed position, the door requires a lock on each side of the door to prevent the unauthorized entry into the garage area.
When a motor operator is attached to the door, the existing locks must be permanently disengaged as the motor cannot lift the door when the lock is engaged. As such, there has thus far been no simple way for the user of such a door to secure the door in the closed position if for example, the user were to be away from the home or business for some length of time, or if the door is located in a high crime area where further protection may be required. If the user wishes to secure the door incorporating the existing locks, the lock must be reassembled and reinstalled on the door which is both time consuming and labor intensive.
While the existing devices are presumably adequate for the purpose for which they were intended, they presented a number of further drawbacks. Specifically, the prior art devices are not adjustably mounted such that mounting the lock is often a time intensive and tedious task, which substantially increases costs. Moreover, the current locks are designed to accept a cable of a given length, and thus a variety of cable lengths are stocked by the door installer, which further increased operation costs to both the manufacturers of overhead doors, as well as the installers.
Therefore, a need exists for an overhead door lock which may be used with both a torsional and extension spring overhead door, as well as with both manually operated, and motor operated doors. Moreover, the need exists for a lock which may be used with a motor operator and may be releasably moved to a lockout, or disengaged and inoperative position, and which the lock may easily be placed in an operative locking position when the user requires extra security. Moreover, the need exists for a lock which may be installed on doors having a variety of sizes.